NASA: Last Decade Warmest on Record 2009 was second warmest year since 1880 By Nx Doyle, Newser User Posted Jan 22, 2010 5:00 AM CST Promoted on Newser Jan 22, 2010 5:00 AM CST 39 comments Comments (AP) (User Submitted) – The decade ending in 2009 was the warmest since modern record-keeping began in 1880, according to new data released by NASA. Based on surface temperature, the year 2005 was the hottest on record, followed by 2009. The data showed an upward temperature trend of about 0.36 degrees Fahrenheit per decade over the last 30 years. Average global temperatures have risen by about 1.5 degrees Fahrenheit since 1880. “When we average temperature over 5 or 10 years to minimize that variability,” NASA climatologist James Hansen tells the New York Times, “we find global warming is continuing unabated.” The Times notes that a separate analysis from a different NASA office, based on land and sea measurements, has 2009 tied with 2005 as the fifth warmest year on record, but concurs in finding the last decade the warmest ever measured.